Re-live one of the greatest stories in motorsport during the 2011 season, The Mobil 1 Car Swap.

The event featured NASCAR Sprint Cup Champion Tony Stewart, and Vodafone McLaren Mercedes Formula 1 driver Lewis Hamilton ... each coming to terms with the other's wheels in a friendly - but very competitive - drive off.  Watch the whole story right here and find out whether they were able to answer that age-old question:  What's better F1 or NASCAR?